This invention relates to improvements in the cooking of a food product in the presence of a radiant energy source and, more particularly to a method and apparatus for controlling distribution and power within the cells of a device for promoting the uniform heating of a food product in a radiant energy field.
The use of radiant energy for cooking, particularly in connection with a microwave oven, has become widespread in recent years. An estimated 66% of the 88 million American households now have microwave ovens and, in the post World War II period, microwaves have been the fastest growing appliance tracked by the Association of Home Appliance Manufacturers. Microwave cooking has reached this level of popularity primarily because food products can be heated quickly and conveniently without the inconvenience of a lengthy meal preparation. The energy in a microwave oven, however, is not distributed equally throughout the cavity of the oven and this unequal distribution causes some areas in the oven to be warmer than others. As a consequence, the food product or products in those areas become hotter resulting in significant temperature differences between separate portions of the food products or within a single portion of a food product.
Many attempts have been made to equalize microwave heating of food products. For example, stirring reduces the unequal heating effects, but there are many food products that cannot easily be stirred. Rearranging, or rotating, the food product within the oven cavity also can reduce the unequal heating effects, but the food product generally must be moved often to cook even substantially uniformly, a procedure that greatly reduces the convenience aspect of microwave cooking. Automatic devices to rotate the food products have been provided, but are not totally successful and add complexity and cost to the microwave units.
Reflective cells, as in parent application Ser. No. 765,374, provide movable reflectors for reflecting the microwaves. The reflectors are movable with variations in the response of a temperature sensor, so that the reflectors vary the direction of the reflected microwaves relative to the food product and vary the concentration of the reflective microwaves incident on the food product to promote uniform heating.
Parent application Ser. No. 019,216 provides a simplified device for the uniform heating of a food product that can be utilized in connection with a conventional radiant energy source such as a microwave oven. The device also can be utilized in connection with a commercial conveyor belt system wherein the food product is placed on the trays of the device, and the trays are thereafter passed through a radiant field. This conveyor application is useful in a commercial cooking environment such as an institution or in the production of precooked food products.
The present invention provides a method nd apparatus to control distribution and power within the cells of a device such as parent application Ser. No. 019,216 for promoting the uniform heating of a food product in a radiant energy field.